Stock feeder

ABSTRACT

A strip of stock is precisely advanced into a punch press or other processing machine by a set of fluid diaphragm actuated grippers, one of which is supported for reciprocating movement relative to the other. The reciprocating gripper is connected by a link to an adjustable eccentric fitting mounted on the shaft of a rotary fluid actuator or motor. The grippers are alternately actuated by a fluid control system which includes a main control valve having a depressible valve member. The fluid control system is also effective to oscillate the rotary actuator in response to a predetermined fluid pressure produced alternately within the grippers and to provide for releasing the fluid in both of the grippers when the main control valve actuating member is further depressed.

United States Patent 1191 Leis 1 Nov. .12, 1974 STOCK FEEDER PrimaryExahzinerC. W. Lanham Assistant ExaminerRobert M. Ro ers 76 I 1; Ath F.L.F.L g 1 men or 2 gigs s, g D ga O Attorney, Agent, or Firm-Jacox &Meckstroth Ohio 45414 7 s C 5 AB TRA T [22] Filed: July 23, 1973 1 Astrip of stock 15 precisely advanced into a punch PP 381,502 press orother processing machine by a set offluid diaphragm actuated grippers,one of which is supported 52 U.S.Cl 72/6 72/422 226/150 forreciprocating movement YehhiYe to the other- The 226/162 reciprocatinggripper is connected by a link to an ad- 51 1m. (:1 821d 43/10 Jumbleeccentric fitting mounted the Shaft of [58] Field of Search 0 72/422 DIG11 423 tary fluid actuator or motor. The grippers are alternatelyactuated a Control system ll'l- 13/1 13 cludes a main control valvehaving a depressible valve member. The fluid control system is alsoeffective to [56] References Cited oscillate the rotary actuator inresponse to a predetermined fluid pressure produced alternately withinthe UNITED STATES PATENTS grippers and to provide for releasing thefluid in both 2: 3 226/162 of the grippers when the main control valveactuating a an 3,793,972 2 1974 Miller 226/[50 member further depressed15 Claims, 13 Drawing Figures PAIENTEBHuv 12 2914 3.84639? SHE? 10F 2FIG-7' I STOCK FEEDER The present invention relates to a stock feeder ofthe general type disclosed in US. Pat. No. 3,597,959 which issued to theinventor of the present invention. In such a stock feeder, it has beenfound desirable to provide for advancing the stock in precisestep-by-step increments which can be conveniently adjusted, and toprovide for smooth high speed operation of the feeder without anysignificant vibrations so that precision feeding is maintained. It isalso desirable for the stock feeder to provide for advancing the stockat a rate which is independent of the rate of movement of a component ofthe machine receiving the stock, and to provide for a compact mechanismwhich produces substantial gripping and feeding forces.

In addition, when a stock feeder is usedfor feeding stock provided withpilot holes for receiving precision alignment pilot pins projecting froma punch, it is also desirable for the stockfeeder to provide forreleasing the gripping force exerted on the stock as the pilot pinsenter the pilot holes so that the stock is free to shift slightly and beprecisely aligned by the pilot pins. While various forms of stockfeeders have been either proposed or used in addition to the stockfeeder shown in the above patent, for example, as shown in US. Pat. No.3,038,645, it has been found that none of these stock feeders providesall of the desirable features mentioned above.

SUMMARY OF THE INVENTION The present invention is directed to animproved stock feeder which provides all of the desirable featuresmentioned above and which is adapted to be operated from a fluid supplysuch as a supply of pressurized air. In particular, the stock feeder ofthe invention is compact and constructed to operate at a high speed withminimum vibrations and jolts to the stock so that the stock may beadvanced in rapid step-by-step increments without slippage of the stockrelative to the stock feeder. The stock feeder is also constructed toapply a substantial gripping force so that only an edge portion of thestrip may be gripped thereby permitting the advancement of a striphaving substantial width. As another important feature, the stock feederof the invention provides a fluid operated control system which assurespositive gripping of the stock before either forward or reverse movementof the reciprocating stock gripper. In addition, the stock feederprovides for automatic releasing of a stock strip having pilot holes asthe locating pilot pins enter the holes.

In general, the above features and advantages are provided in a stockgripper which incorporates a hous ing or body for supporting astationary diaphragm actuated stock gripper and two parallel spacedguide rods on which is mounted a movable diaphragm actuated stockgripper. The body encloses an oscillating vanetype fluid-actuator ormotor which has a shaft supporting an adjustable bracket eccentricallyconnected by a link member to the movable stock gripper. The housing orbody also encloses a fluid control system including a main control valvehaving a valve member adapted to be depressed by downward movement of acomponent of a press receiving the stock. The control valve systemprovides for automatically oscillating the fluid motor shaft in responseto a predetermined fluid pressure produced alternately in the diaphragmactuated stock grippers. Further depression of the main control valvemember is effective to actuate a dumping valve so that the stock isreleased by both stock grippers and may be precisely positioned by pilotpins carried by a punch.

Other features and advantages of the invention will be apparent from thefollowing description, the accompanying drawings and the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a stockfeeder constructed in accordance with the invention; 2

FIG. 2 is an elevational view of the right end of the stock grippershown in FIG. I;

FIG. 3 is an elevational view of the left end of the stock gripper shownin FIGS. 1 and 2';

FIG. 4 is an elevational front view of the stock gripper shown in FIGS.l-3; 6

FIG. 5 is a section taken generally on the line 5-5 of FIG. 1; j

FIG. 6 is a fragmentary section taken generally on the line 6-6 of FIG.5;

FIG. 7 is a section taken generally on the line 77 of FIG. 5';

FIG. 8 is asection taken generally on the line 8-8 of FIG. I;

FIG. 9 is a section'taken generally. on the line 9-9 of-FIG. 1;

FIG. '10 is a fragmentary section takenlgenerally on I the line 10-10 ofFIG. 3; x I

FIG. 11 is a section taken generally on the line l111 of FIG. 1 j I FIG.12 is a section taken generally on the line 1212 of FIG. 1; and i FIG.13 is a diagrammatic illustration of the fluid control system foroperating the stock gripper shown in FIGS. 1-12.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The stock gripper shownin elevation in FIGS. l-4, includes a cast metal housing or body 20formed by a main body portion 22 which integrally connects parallelspaced and forwardly projecting endbody portions 23 and 24. The end bodyportion 24 includes an outwardly projecting integral L-shaped flange 26which is provided with a set of holes 27 for receiving'screws (notshown) to secure the body 20 to a lower die shoe mounted on a punchpress, as shown in the abovementioned patent, or to another machinewhich receives the stock.

As shown in FIGS. 3 and 11, the end portion 24 of the housing 20 alsoincludes an integral diaphragm housing portion 29 which projectsoutwardly over'the base flange 26 and forms part of a stationary stockgripper 30. The gripper 30 further includes a vertical rod is flat andopposes the upper flat surface of a lower stock gripping shoe 36. Theshoe 36 includes an integral cylindrical portion 37 which projects intoa bore formed within the base flange 26 and is secured by a set screw38. The upper end portion of 'the rod 32 is secured to a circular plate41 (FIG. 11) which engages a flexible rubber diaphragm 42 having anouter peripheral portion secured to the housing portion 29 by a coverplate 44. A compression spring 45 is confined within the housing portion29 and urges upwardly on the plate 41 so that the rod 32 and uppergripper shoe 34 are normally retracted upwardly, opposite to thegripping position shown in FIG. 11. I

A fluid passage 46 is formed within the cover plate 44 and connects witha horizontal passage 47 and a vertical passage 48 formed within the endportion 24 of the housing or body 20. When pressurized fluid or air issupplied through the passages 48, 47 and 46 to the top side of thediaphragm 42, the upper gripping shoe 34 is pressed downwardly towardsthe lower shoe 36 for positively gripping the stock which is illustratedin FIGS. 1-4 in the form of a continuous sheet metal strip S.

A pair of vertically spaced horizontal guide rods 52 are rigidlysupported on opposite ends by the end portions 23 and 24 of the body 20as shown in FIGS. 1 and 4. The rods 52 support a movable or slidablestick gripper 55 (FIGS. 4 and 12) which is constructed in a mannersimilar to the stationary sock gripper 30 except that it includes agenerally C-shaped body or carriage 56 (FIG. 12) which is supported forreciprocating movement by the guide rods 52. The movable stock gripper55 incorporates components which are identical to the components of thestationary stock gripper 30 and are therefore indicated by correspondingreference numbers. In place of the cover plate 44 of the stationarygripper 30, the movable stock gripper 55 includes a cover plate 58 whichreceives pressurized fluid or air through an L shaped fitting 59 and aflexible hose or tube 61.

As shown in FIGS. 1 and 2, the stock or strip S is directed between theupper shoe 34 and lower shoe 36 of each of the stock grippers 30 and 55by-a pair of guide rollers 63. The rollers 63 are mounted for lateraladjustments within a series of corresponding slots 64 formed within thehorizontal flange of an angle-shaped elongated support bracket 66. Thevertical flange of the bracket 66 is secured to the body end portion 23by a set of screws 67 (FIG. 2) which extend through correspondingadjustment slots 68 formed within the flange. The adjustment of therollers 63 on the bracket 66, and the horizontal adjustment of thebracket 66 on the body 20, provide for accommodating stock strips ofvarious widths, for example, between one-eighth inch and six inches.

The housing or body 20 also encloses a rotary fluid actuator 70 (FIGS.and which is constructed similar to an oscillating vane-type fluidmotor. The actuator 70 includes a shaft 72 which is positioned withinthe center of a cylindrical chamber 73. The shaft 72 is rotatablysupported by the body and a closure plate 74 cavities which are adaptedto receive alternately the opposite edge portions of the shoe 79 whenthe actuator vane 78 is oscillated. As shown in FIG. 5, the outer endsurfaces of the projections 84 are closely fit relative to the innercylindrical surface of the shoe 79 so that the cavities form fluiddampening or air cushion chambers at the limits of arcuate movement ofthe actuator vane 78 and sliding shoe 79.

A slide block or bracket 88 (FIGS. 9, 10 and 12) is secured to theprojecting end portion of the shaft 72 and slidably supports aconnectorelement 89 (FIGS. 9 and 12) which is linearly adjustable relative to thebracket 88 by releasing clamping screws 92 (FIG. 9) and adjusting a setscrew 93 (FIG. 12) with a suitable Allen wrench. The connector elementv89 has a set of eccentrically located holes 94 (FIG. 9) for selectivelyreceiving a pin 96 which forms a pivot connection for 'one end portionof a link member 98. The connecting pin 96 is retained within one of theholes 94 by the head of a screw 99. The outer end portion of the linkmember 98 is pivotally connected by a pin 101 to an ear of the carriage56 of the movable gripper 55, as shown in FIG. 10. When the pin 96 ispositioned within the innermost hole 94(FIG. 9), the adjustment of theset screw 93 provides a first range of movement of the gripper 55, forexample, between zero and one inch. When the connecting pin 96 ispositioned within the outermost hole 94, the adjustment of the set screw93 provides for reciprocation of the gripper 55 within a second range ofmovement, for example, 1 inch to 2 inch travel.

As mentioned above, the stock feeder of the invention is adapted to beoperated by a source of pressurized fluid such as air supplied underpressure at 100 psi. This supply of pressurized air is effective tooperate the stock grippers 30 and 55 and the rotary actuator 70 in apredetermined sequence in response to a fluid 0r pneumatic controlsystem shown somewhat diagramsecured to the body 20 by a series ofscrews 76. An actuating vane 78 is formed as an integral part of theshaft 72 and carries an arcuate shoe 79 (FIG. 5) which slidably engagesthe inner cylindrical surface defining the chamber 73. An arcuate shapedblock or fitting 82 projects into the chamber 73 and is supported by aset of screws extending through the closure plate 74.The fitting 82includes a set of projections 84 which form stops for limiting therotative movement of the actuating vane 78. The projections 84 alsocooperate with the cylindrical surface defining the chamber 73 to definematically in FIG. 13. This control system includes a main actuator orcontrol valve 105 (FIG. 5) which includes a pin-like actuating valvestem or member 106 slidably supported within a vertical chamber or bore107 formed within the body 20. The valve member 106 projects upwardlythrough a retaining collar 108 which is secured within a counterboreformed within the body 20.

A hollow cylindrical cap member 110 is slidably mounted on the upperportion of the valve member 106 and has external threads for receivingan adjustable sleeve 112. The sleeve is clamped to the cap member 110 bya set screw 113 and includes a vertical slot 114 which receives a crosspin 116 extending diametrically through the valve stem or member 106.The pin 116 has a length slightly less than the CD. of the cap member110 so that the sleeve 112 is free to move with the cap member 110 onthe valve member 106. A compression spring 117 is confined within a holeformed with the top of the valve member 106 and urges upwardly on thecap member 110 until the lip 114 of the sleeve 112 engages the cross pin116.

The lower portion of the valve member 106 includes a set ofcircumferential grooves 121 and 122 which define corresponding chambersand which are sealed by an O-ring 123 located within another grooveformed in the valve member 106. A bore 126 of reduced diameter, projectsfrom the bottom of the bore 107, and a compression spring 128 projectsupwardly from the bore 126 into a hole or passage 129 extending axiallywithin the valve member 106 to a radial port 131. The spring 128 urgesthe valve member 106 upwardly from the depressed position shown in FIG.to a normal position where a shoulder on the valve member engages thecollar 108. The supply fluid or air is directed" into the housingthrough a passage 132 (FIG. 5). An upper passage 133 and a lower passage134 extend horizontally from the bore 107 to the rotary actuator 70through a pair of corresponding pressure actuated control valves 135(FIGS. 5-7). A corresponding set of connecting air passages 137 (FIG. 5)are formed within the fitting 82 and extend in crossing nonintersectingdirections to the chamber 73 on opposite sides of the actuating vane 78and shoe 79.

Referring to FIGS. 6 and 7, each of the pressure actuated control valves135 includes a tubular fitting 139 which is inserted into a bore 141formed within the main body portion 22. Each fitting 135 includes aninner frusto-conical valve seat 143 against which a ball 144 isurged bya light compression spring 147. The spring 147 extends between the ball144 and a plug-like fitting 148 forminga closure for the outer end ofthe bore 141. Another compression spring 151 extends between the innerend of the bore.141 and the inner end of the fitting 139 and exerts anaxial forcesubstantially greater than that of the spring 147 so that thefitting 139 seats normally against the fitting 148, as illustrated bythe upper valve 135 shown in FIG. 7'. A radial port 154 (FIG. 6) isformed within each fitting 148 and is connected by a correspondingpassage 156 to the corresponding passage 133. A vertical passage 158 isformed within the body portion 22 and connects the upper passage 133 toan elbow fitting 159 (FIGS. 1 and 4) which receives the opposite end ofthe flexible conduit or hose 61. Another angular passage 162 (FIG. 6)connects the inner end of each bore 141 to the corresponding passage-133or 134 and the corresponding passage 137 within the fitting 82 of therotary actuator 70.

Referring to FIG; 8, another vertical bore 166 is formed within the bodyportion 22 adjacent the bore 107, but is somewhat smaller in diameter. Avalve plunger or member 168 is slidably supported within the bore 166and is urged upwardly against the collar 108 by a compression spring 169extending between the bottom of the bore 166 and the inner end of thevalve member 168. A pin 172 projects upwardly from the upper end portionof the valve member 168 through an opening within the collar 108 and isadapted to be engaged by the sleeve 112 when the cap member 110 on theactuator valve member 106, is further depressed, as will be explainedlater.

A circumferential groove 173 (FIG. 8) is formed on the lower end portionof the 'valve member 168 and provides a normally open fluid path forpressurized air from the passage 134 through a passage 174 (FIG. 13) tothe passages 47 and 48 extending to the stationary stock gripper 30. Anaxially extending hole 176 is formed within the lower end portion of thevalve member 168 and connects with a radial port 177 at its inner orupper end. When the valve member 168 is depressed against the spring 169by depressing the pin 172, the port 177 connects with the passage 174,and the pressurized air to the stationary gripper 30 is exhaustedthrough the port 177, hole 176, the inner end of the bore 166 and anexhaust passage 178 which connects with the reduced bore 126 of the mainactuator or control valve and is open to atmosphere as shown in nectionwith FIG. 13 which illustrates the condition of the control system atthe end of the forward stroke of the stock gripper 55. Asmentioned-above, pressurized fluid or air is supplied to the passage 131(FIG. 5 After the valve member 106 is depressed downwardly, for example,with the downward movement of the upper die shoe on a punch press, thepressurized air is supplied through the groove 122 and the passage 134(FIG. 5) to the lower pressure actuated valve (FIG. 7). The valve 135 isnormally closed so that the air does not continue to flow through thepassage 134 to the rotary actuator 70. The pressurized air within thepassage 134 is supplied through the passage 174 and the. groove 173within the valve member 168 to the passages 48, 47 and 46 connected tothe chamber above the diaphragm 42 of the stationary stock gripper 30.

The air pressure above the diaphragm 42 causes the corresponding rod 32and shoe 34 to move downwardly so that the stock orstrip S is positivelygripped or clamped with substantial force by the shoes 34 and 36 of thestationary stock gripper 30. As soon as the air pressure within thegripper 30 reaches the air supply pressure and the stock ispositivelygripped, the lower valve 135 moves to an open position (FIG. 7) as aresult of an inward movement of the fitting 139 against the forceexerted by the compression spring'151. The pressurized air thencontinues through-the passage 134 to the corresponding passage 137 (FIG.5') so that one side of the vane 78 of the rotary actuator 70'ispressurized. This causes the vane 78 and the shaft 72 to rotateclockwise (FIG. 5) approximately 180 so that the corresponding passage137 and passage 133 and through the check valve within the upperpressure actuated valve 135 (FIG. 5). The air within the passage 133(FIG. 5) is directed into the groove 121 of the valve member 106 andthrough the port 131 and the center hole 129 within the valve member 106to the exhaust passage 178. After the stock gripper 55 has reached therearward end of its stroke or returned to its home position, and thevalve member 106 is moved upwardly, pressurized air is directed from thesupply passage 131 through the groove 122 and the upper passage 133(FIG. 5) to the upper pressure actuated valve 135. The pressurized airis then directed to the chamber above the diaphragm .42 for the movablestock gripper 55 so that the stock or strip S is gripped by the gripper55. The upward movement of the valve member.

106 is also effective to release the air pressure-behind the diaphragm42 on the stationary stock gripper 30 by an exhaust of the air throughthe passages 134 and 178 under the lower end of the valve member 106.After the stock is gripped by the movable stock gripper 55, the rotaryactuator 70 is pressurized on the opposite side of the vane 78 so thatthe stock is advanced by forward movement of the stock gripper 55. Thusthe stock S is automatically advanced in precise step-by-step incrementsin response to actuation of the main control valve 105.

As mentioned above, it is sometimes desirable to have the stock releasedfrom both of the stock grippers 30 and 55 when the stock is providedwith pilot holes for receiving pilot locating pins in the die set. Thisfeature is accomplished by adjusting the axial position of the sleeve112 on the cap member 110 so that a slight over travel of the cap member110 after the valve member 106 has reached its lower position (FIG.causes the sleeve 112 to depress the pin 172 (FIG. 8) and the valvemember 168. This causes the port 177 to align with the passage 174 andexhausts the passage 174 to atmosphere'through the exhaust passage 178.The release of the air pressure within the passage 174 is effective torelease the pressure within the passages 46-48 so that the diaphragm 42and the gripper rod 32 of the stock gripper 30 are urged upwardly by thecompression spring 45. Thus when the passage 174 is open to atmosphereor exhausted through the valve member 168, there is no air pressure toboth of the grippers 30 and 55 and the corresponding gripping shoes 34are retracted upwardly for releasing the strip 8. As soon as theadjustable sleeve 112 moves upwardly with the cap member 110, the valvemember 168 (FIG. 8) returns to its normal upper position (FIG. 8) by thespring 169 so that the passage 174 is open to the passages 46-48 throughthe groove 173, as illustrated in FIG. 13.

From the drawings and the above description, it is apparent that a stockfeeder constructed in accordance with the present invention providesdesirable features and advantages. For example, in addition to thesimple harmonic movement of the stock gripper 55, which provides for agradualacceleration and deceleration of movement of the stock gripper atthe limits of its stroke, each of the stock grippers 30 and 55 providesa substantial gripping force of the stock in a compact space as a resultof the corresponding diaphragmactuated gripping shoe 34.

Another important feature is provided by the automatic control systemwhich assures that the stock is positively gripped with the substantialforce before the stock gripper 55 is advanced or retracted. That is, thepressure-responsive valves 135 provide for alternately actuating thestock grippers 30 and 55 before the rotary actuator 70 is operated oroscillated to assure that there is no movement of the stock gripper 55before the stock is positively gripped by the gripping shoes of at leastone of the stock grippers.

The rotary actuator 70 also incorporates an air cushion or dampeningmeans as a result of the cooperation between the shoe 79 of the actuatorand the inner pockets or chambers defined by the projections 84 of theactuator fitting 82. That is, the stock gripper 55 not only moves withgradual acceleration and deceleration at the end of each stroke, but anair cushion is provided at each end of the stroke. As a result, thestock feeder operates with minimum vibration during reciprocatingmovement of the stock gripper 55.

A further advantage is provided by the air dumping or releasing valvesystem shown in FIG. 8. As men tioned above, slight over travel of themain control valve head or cap member 110 is effective to move the valvemember 168 so that the air pressure to the stationary stock gripper 30,is released at the same time the air pressure to the movable stockgripper 55 is released. This feature is desirable in feeding a stockhav- While the form of stock feeder herein described constitutes apreferred embodiment of the invention, it is to be understood that theinvention is not limited to this precise form of stock feeder, and thatchanges may be made therein without departing from the scope and spiritof the invention as defined in the appended claims.

The invention having thus been described, the following is claimed:

1. A device for feeding stock in precise step-by-step increments into ametal working press or the like, comprising a first fluid actuated stockgripper and a second fluid actuated stock gripper, means supporting saidsecond stock gripper for reciprocating movement between predeterminedlimits relative to said first stock gripper, a rotatably supportedshaft, a fluid actuator connected to rotate said shaft, means forconnecting said shaft to said second stock gripper to reciprocate saidsecond stock gripper in response to rotation of said shaft to ef fectgradual acceleration and deceleration of said second stock gripperadjacent said limits, and fluid control means for operating said fluidactuator in response to a predetermined pressure in at least said secondstock gripper.

2. A device as defined in claim 1 wherein each of said first and secondfluid actuated stock grippers, comprises a rod,,and means including aflexible diaphragm for moving said rod axially in responseto theapplication of pressurized fluid on said diaphragm.

3. A device as defined in claim 1 wherein said fluid actuator comprisesa fluid motor including a vane connected to said shaft, and said fluidcontrol means is connected to oscillate said vane of said motor.

4. A device as defined in claim 1 wherein said fluid control means andsaid fluid actuator are effective to oscillate said shaft to causereciprocating movement of said second stock gripper.

5. A device as defined in claim 1 including means for dampening theoperation of said fluid actuator when said second stock gripperapproaches said predetermined limits of movement.

6. A device as defined in claim l wherein said fluid control meanscomprise a plunger type valve including a valve member adapted to bemoved axially in response to movement of a component of the press, andmeans for releasing the pressurized fluid applied to both of said stockgrippers in response to predetermined movement of said valve member.

7. A device as defined in claim 1 wherein said fluid control meanscomprise a main control valve including a valve member adapted to bemoved in response to the movement of a component of the press, saidfluid actuator is effective to osciallate said shaft to effectreciprocation of said second stock gripper, and said fluid control meansfurther include a set of fluid actuated valves which produce alternatingactuation of said first and second stock grippers and oscillation ofsaid shaft in response to movement of said valve member of said maincontrol valve.

8. A device as defined in claim 1 wherein said means supporting saidsecond stock gripper for reciprocating movement, comprise a set ofparallel spaced rods, a housing supporting the end portions of saidrods, and

said fluid actuator comprises an oscillating vane-type fluid motorformed within said housing, and valve means for osciallating said motorin response to alternate actuation of said first and second stockgrippers.

tion of said second stock gripper adjacent said limits,

and fluid control means within said housing for operating said actuatorand said first and second stock grippers in predetermined sequence.

10. A device as defined in claim 9 wherein each of said first and secondfluid actuated stock grippers,

comprises a gripping shoe, and means including a flexible diaphragm formoving said shoe in response to the application of pressurized fluid onsaid diaphragm.

11. A device as defined in claim 9 wherein said control means is alsoeffective to release the fluid pressure to both of said gripperssimultaneously in response to predetermined actuation.

12. A device for feeding stock in precise step-by-step increments into ametal working press or the like, comprising a housing supporting a firstfluid diaphragm actuated stock gripper, a second fluid diaphragmactuated stock gripper, means on said housing and supporting said secondstock gripper for reciprocating movement between predetermined limitsrelative to said first stock gripper, a rotatably supported shaft, afluid actuator connected to rotate said shaft, means for connecting saidshaft to said second stock gripper to reciprocate said second stockgripper in response to rotation of said shaft to effect gradualacceleration and deceler ation of said second stock gripper adjacentsaid limits, fluid control means within said housing and including avalve member adapted to be moved in response to operation of the press,and said fluid actuator and said first and second stock grippers beingactuated in predetermined sequence in response to movement of said valvemember.

13. A device for feeding stock in precise step-by-step increments into ametal working press or the like, comprising a housing supporting a firstfluid actuated stock gripper, a second fluid actuated stock gripper,means on said housing for supporting said second stock gripper forreciprocating movement between predetermined limits relative to saidfirst stock gripper, an oscillating vane-type fluid motor supported bysaid housing and including a shaft, means including an adjustablebracket for connecting said shaft to said second stock gripper forreciprocating said second stock gripper in response to oscillation ofsaid shaft to effect gradual acceleration and deceleration of saidsecond stock gripper adjacent said limits, and fluid control valve meanswithin said housing for oscillating said fluidmotor in response toproducing a predetermined fluid pressure alternately within said stockgrippers.

14. A device as defined in claim 13 wherein said fluid control valvemeans comprises a main control valve including a valve member adapted tobe actuated in response to movement of the press, and a set of pressureresponsive control valves within passages connected to said fluid motor.

15. A device as defined in claim 13 wherein said fluid motor includesmeans for dampening the oscillation of said shaft.

1. A device for feeding stock in precise step-by-step increments into ametal working press or the like, comprising a first fluid actuated stockgripper and a second fluid actuated stock gripper, means supporting saidsecond stock gripper for reciprocating movement between predeterminedlimits relative to said first stock gripper, a rotatably supportedshaft, a fluid actuator connected to rotate said shaft, means forconnecting said shaft to said second stock gripper to reciprocate saidsecond stock gripper in response to rotation of said shaft to effectgradual acceleration and deceleration of said second stock gripperadjacent said limits, and fluid control means for operating said fluidactuator in response to a predetermined pressure in at least said secondstock gripper.
 2. A device as defined in claim 1 wherein each of saidfirst and second fluid actuated stock grippers, comprises a rod, andmeans including a flexible diaphragm for moving said rod axially inresponse to the application of pressurized fluid on said diaphragm.
 3. Adevice as defined in claim 1 wherein said fluid actuator comprises afluid motor including a vane connected to said shaft, and said fluidcontrol means is connected to oscillate said vane of said motor.
 4. Adevice as defined in claim 1 wherein said fluid control means and saidfluid actuator are effective to oscillate said shaft to causereciprocating movement of said second stock gripper.
 5. A device asdefined in claim 1 including means for dampening the operation of saidfluid actuator when said second stock gripper approaches saidpredetermined limits of movement.
 6. A device as defined in claim 1wherein said fluid control means comprise a plunger type valve includinga valve member adapted to be moved axially in response to movement of acomponent of the press, and means for releasing the pressurized fluidapplied to both of said stock grippers in response to predeterminedmovement of said valve member.
 7. A device as defined in claim 1 whereinsaid fluid control means comprise a main control valve including a valvemember adapted to be moved in response to the movement of a component ofthe press, said fluid actuator is effective to osciallate said shaft toeffect reciprocation of said second stock gripper, and said fluidcontrol means further include a set of fluid actuated valves whichproduce Alternating actuation of said first and second stock grippersand oscillation of said shaft in response to movement of said valvemember of said main control valve.
 8. A device as defined in claim 1wherein said means supporting said second stock gripper forreciprocating movement, comprise a set of parallel spaced rods, ahousing supporting the end portions of said rods, and said fluidactuator comprises an oscillating vane-type fluid motor formed withinsaid housing, and valve means for osciallating said motor in response toalternate actuation of said first and second stock grippers.
 9. A devicefor feeding stock in precise step-by-step increments into a metalworking press or the like, comprising a housing supporting a first fluidactuated stock gripper, a second fluid actuated stock gripper supportedby said housing for reciprocating movement between predetermined limitsrelative to said first stock gripper, a rotary fluid oscillatingactuator within said housing and including a shaft, means for connectingsaid shaft to said second stock gripper to reciprocate said second stockgripper in response to oscillation of said shaft to effect gradualacceleration and deceleration of said second stock gripper adjacent saidlimits, and fluid control means within said housing for operating saidactuator and said first and second stock grippers in predeterminedsequence.
 10. A device as defined in claim 9 wherein each of said firstand second fluid actuated stock grippers, comprises a gripping shoe, andmeans including a flexible diaphragm for moving said shoe in response tothe application of pressurized fluid on said diaphragm.
 11. A device asdefined in claim 9 wherein said control means is also effective torelease the fluid pressure to both of said grippers simultaneously inresponse to predetermined actuation.
 12. A device for feeding stock inprecise step-by-step increments into a metal working press or the like,comprising a housing supporting a first fluid diaphragm actuated stockgripper, a second fluid diaphragm actuated stock gripper, means on saidhousing and supporting said second stock gripper for reciprocatingmovement between predetermined limits relative to said first stockgripper, a rotatably supported shaft, a fluid actuator connected torotate said shaft, means for connecting said shaft to said second stockgripper to reciprocate said second stock gripper in response to rotationof said shaft to effect gradual acceleration and deceleration of saidsecond stock gripper adjacent said limits, fluid control means withinsaid housing and including a valve member adapted to be moved inresponse to operation of the press, and said fluid actuator and saidfirst and second stock grippers being actuated in predetermined sequencein response to movement of said valve member.
 13. A device for feedingstock in precise step-by-step increments into a metal working press orthe like, comprising a housing supporting a first fluid actuated stockgripper, a second fluid actuated stock gripper, means on said housingfor supporting said second stock gripper for reciprocating movementbetween predetermined limits relative to said first stock gripper, anoscillating vane-type fluid motor supported by said housing andincluding a shaft, means including an adjustable bracket for connectingsaid shaft to said second stock gripper for reciprocating said secondstock gripper in response to oscillation of said shaft to effect gradualacceleration and deceleration of said second stock gripper adjacent saidlimits, and fluid control valve means within said housing foroscillating said fluid motor in response to producing a predeterminedfluid pressure alternately within said stock grippers.
 14. A device asdefined in claim 13 wherein said fluid control valve means comprises amain control valve including a valve member adapted to be actuated inresponse to movement of the press, and a set of pressure responsivecontrol valves within passages connected to said fluid motOr.
 15. Adevice as defined in claim 13 wherein said fluid motor includes meansfor dampening the oscillation of said shaft.